12
Q:

# A sum of Rs.1890 has to be used to give 9 prizes to the customers of a super market for their overall academic purchases. If each prize is Rs.30 less than its preceding price, what is the least value of the price ?

 A) 90 B) 95 C) 85 D) 80

Explanation:

Let the least value of the prize = Rs. x

Then the next value of the prize is x+30 , x+60, x+90, ....x+240.

Given total amount of cash prizes = Rs.1890

--> x + (x+30) + (x+60) + (x+90) + ....+ (x+240) = 1890

--> 9x + (30 + 60 + 90 + 120 + 150 + 180 + 210 + 240) = 1890

--> 9x + 30(1 + 2 + 3 + 4....+ 8) = 1890

--> 9x + 30(36) = 1890

--> 9x = 810 --> x=90

Hence the least value of the prize x=90

Q:

What is

 A) 0 B) 42 C) 50 D) 57

Explanation:

Given 7 + 7/7 + 7 x 7 - 7

By using BODMAS rule,

7 + 1 + 7 x 7 - 7

= 8 + 49 - 7

= 57 - 7

= 50.

Hence 7 + 7/7 + 7 x 7 - 7 = 50.

1 163
Q:

Find the Value of ?

 A) 81 B) 77 C) 73 D) 89

Explanation:

This can be done in a method called Approximation.

Now,

5 226
Q:

Can you Solve  =

 A) 112 B) 56 C) 0 D) 98

Explanation:

8 210
Q:

The last two digits of ${\mathbf{2151}}^{\mathbf{415}}$?

 A) 81 B) 61 C) 91 D) 51

Explanation:

Unit digit of this expression is always 1 as the base ends with 1.

For the tenth place digit we need to multiply the digit in the tenth place of the base and unit digit of the power and take its unit digit.

i.e, tenth place digit in 2151 is 5 and

tenth place digit in power 415 is 1

And the units digit in the product of 5 x 1 = 5

Therefore, last two digits of ${\mathbf{2151}}^{\mathbf{415}}$ is 51.

4 297
Q:

What is the value of P in the following Equation ?

 A) 3.9 B) 4.1 C) 3.7 D) 4.5

Explanation:

Given equation is

Here it is in the form of

Here m = 2.5 , n = p, m+n = 7

=> 2.5 + p = 7

=> p = 7 - 2.5

=> p = 4.5

8 484
Q:

The solution of 3(2u + v) = 7 uv and 3(u + 3v) = 11 uv is _____

 A) u = 1, v = 0 B) u = 1, v = 3/2 C) u = 0, v = 3/4 D) u = 0, v = 1

Explanation:

Using Trial and error method,

From the options  u = 1, v = 3/2 satisfies both the equations.

16 443
Q:

What approximate value will come in place of question mark (?) in the following question ?

(49.001)2  = ?

 A) 2500 B) 2400 C) 2600 D) 2300

Explanation:

Given (49.001)2  = ?

=> =~ 49 x 49

=~ 2401

=~ 2400

12 519
Q:

Find the quadratic equations whose roots are the reciprocals of the roots of $2{x}^{2}+5x+3$?

A)  $3{x}^{2}+5x+2=0$

B) $5{x}^{2}+3x+2=0$

C) $3{x}^{2}-5x-2=0$

D)  None

 A) A B) B C) C D) D

Explanation:

The quadratic equation whose roots are reciprocal of $2{x}^{2}+5x+3=0$ can be obtained by replacing x by 1/x.

Hence, 2(1/x)(1/x)+ 5(1/x) + 3 = 0

=> $3{x}^{2}+5x+2=0$